Worksheets11. Inspection & Testing
Total questions: 46
Worksheet time: 23mins
Why should all documentation given after initial verification be kept in a safe place?
Adds value if selling the property
To reduce insurance premiums
As reference for any persons inspecting any work at a later date
To comply with any local authority inspections
For safety reasons, what is the recognised status for undertaking and signing off inspection and test work?
a skilled person
an instructed person
a person qualified in PAT testing
a person who is a member of the IET
On which two documents is prospective fault current recorded?
Minor Electrical Installation Works Certificate and Schedule of Inspections
Electrical Installation Certificate and Schedule of test results
Electrical Installation Certificate and Minor Electrical Installation Works Certificate
Schedule of Inspections and Schedule of test results
Which is one of the documents that must accompany an Electrical Installation Certificate?
Minor Electrical Installation Works Certificate
Landlords safety certificate
Electrical indemnity certificate
Schedule of Inspections
On completion of electrical work, all appropriate documentation should be
Given to the building inspector
Retained by the electrician
Left next to the mains position
Given to the person ordering the work
Functional testing may involve
Insulation resistance testing
Disconnecting an appliance
Turning on a light switch
Continuity testing
A check for phase sequence at the main intake to a three phase installation indicated a result of L1, L3, L2. The correct orientation at each subsequence distribution board is
L1, L3, L2
L2, L3, L1
L2, L1, L3
L3, L2, L1
One reason for testing that the phase sequence is the same across an installation is
The hold-on relay in motor starters can be connected to the correct phase
Fluorescent lamps will not make moving machinery appear stationary
The installer will know the direction of rotation of three phase machines
Power factor correction capacitors can be connected the right way around
The table shows the results for a test carried out on a 30mA RCD to BSEN 61008, that is being used for additional protection. Which statement best describes the result of the test?
The RCD fails as it should trip within 0.4s at 15mA leakage
The RCD fails as it should trip within 300ms at 30mA leakage
The RCD passes as it trips quicker than all the required tripping times
The RCD fails as it should trip within 0.02s at 150mA leakage
What is the minimum permitted value to be found on a protective device at the origin of 230V single phase circuit where Ze is 0.12Ω?
1500
6000
3000
10000
The measured value of prospective fault current for a single phase installation can be checked by
Voltage divided by Ze
Voltage divided by the demand load
Looking in BS7671 IET Wiring Regulations
Looking in BS7671 One Site Guide
Calculate the maximum permitted value of earth fault loop impedance for a circuit when the maximum tabulated value quoted in BS7671 is 2.4Ω.
1.92 Ω
4.84 Ω
2.16 Ω
2.42 Ω
If Ze is to be obtained by direct measurement, the
Main switch is off and the earthing lead is connected
Main switch is off and the earthing lead disconnected
Main switch is on and the earthing lead connected
Main switch is on and the earthing lead disconnected
Which of these best describes the fault current return path to the origin of the supply, for a TT earthing system?
The fault current returns to the origin via the general mass of earth
The fault current returns to the origin via a separate earthing conductor
The fault current returns to the origin via a combined earth and neutral conductor
The fault current returns to the origin via the line and neutral conductor
The three results from an earth electrode tester on a TT system were 100Ω, 110Ω, 90Ω. What value is recorded on the schedule of test results?
100 Ω
110 Ω
90 Ω
200 Ω
Which instrument is used to confirm the polarity of the incoming supply?
An earth fault loop impedance tester
An approved voltage indicator
A low resistance ohm meter
An insulation resistance meter
The test for polarity must not be used to check
That single pole devices are in the line conductor only
If the supply to the installation is live
If wiring is correctly connected
If the centre-contact of an Edison Screw lamp holder is connected to the line conductor
When a cables length is reduced, the effect on the insulation resistance will be to
Stay the same
Reduce
Increase
Fluctuate
A circuit is being supplied with a voltage of up to and including 500V. Identify the minimum expected insulation resistance test value, and the correct scale of measurement.
0.5 MΩ
1.0 MΩ
500 MΩ
230 V
What is the best action to take when carrying out an insulation resistance test on a surge protection device that is vulnerable to the test voltage and cannot be reasonably removed?
The test voltage is reduced to 250V and the test is carried out as normal with a requirement of a minimum value of 1MΩ
The test voltage is reduced to 250V and the test is carried out as normal with a requirement of a minimum value of 0.5MΩ
The test is carried out differently with measurement taken from line to CPC and neutral to CPC but not from line to neutral
If the circuit is visible along the whole of its length, it is not tested but is subject to a thorough visual inspection instead
What is the effect on the overall resistance if two cables are connected in parallel?
Decreases
Remains the same
Increases
Increase momentarily then decreases
A ring final circuit test is carried out. During step 1 of the test the resistance of the end to end loops at the consumer unit are r1: 0.8 Ω and r2: 1 Ω. If the circuit has no spurs, what is the expected value of R1 + R2?
0.6 Ω
0.45 Ω
0.3 Ω
0.9 Ω
Which is not an advantage of test method 1, when measuring the continuity of protective conductors?
There is no long wandering lead to present a hazard
Correct polarity can be checked at the same time
Continuity of bonding conductors is easily measured
R1 + R2 can be measured directly at the same time
The low resistance of the protective bonding conductors should be verified to ensure that
The RCD (Residual Current Device) operates within the required 30ms
The protective device operates within the required time
Touch voltage is limited in the event of a fault to earth
Touch voltage is limited in the event of a short circuit
The sequence of testing in GN3 is carried out during initial verification of new build because
The result of a previous test may influence the next test
This is the sequence laid down by the Building regulations and cannot be changed
GN3 is a statutory document and must be followed in that order
This is the sequence laid down by the Electricity at Work Regulations and cannot be changed
When conducting an insulation resistance test on a whole distribution board as allowed under certain conditions in BS 7671. The result was 1.2MΩ. What would be the most appropriate action to taken in this situation?
Record the value, issue a code 1 and lock off the isolator
Record the value and take no further action
Record the value, tell the client that it meets the requirements and the premises will need testing again in three months
Disconnect the circuits and test individually as possibly a circuit is deteriorating
Why are details of the test instrument included on the schedule of test results?
In order to compare test results from that instrument with others
So that the test can be repeated with exactly the same test instrument
So that calibration records for the instrument can be checked if necessary
To find out if the test instrument is reading correctly on some tests
For a circuit having an R1 + R2 reading of 0.37 Ω the test instrument and range should be
An insulation resistance test instrument set to the maximum range
A low resistance ohmmeter set to the minimum range
An insulation resistance test instrument set to the minimum range
A low resistance ohmmeter set to the maximum range
Which dead tests should be performed on a ring final circuit?
Continuity, Insulation Resistance, Polarity
Continuity, Polarity, CPC and RCD testing
Insulation Resistance, Polarity, Earth Fault Impedance
Continuity, Polarity, Earth Loop Impedance
What is the minimum IP rating for correctly rated and protected current, using equipment in zone 1 of a room containing fixed bath if there are no water jets?
IP X5
IP 4X
IP X4
IP 5X
What is not allowed for use on a construction or demolition site under normal conditions?
Reduced low voltage
A PME facility as a means of earthing
SELV
PELV
A radial power circuit has been installed without any spurs, and protected by a 32A, type B circuit breaker. What is the minimum c.s.a of the live conductors?
4mm²
6mm²
1.5mm²
2.5mm²
When inspecting a 10mm² single core cable used as a protective conductor, it must be checked that it is constructed from
Aluminium
Copper
Chromium
Steel
The inspector’s sense of touch will help to identify
If the MCB’s correctly selected
A loose connection
If the cables have been correctly identified
The correct connection of equipment
When inspecting a system that uses double insulation as a protective measure, what symbol would be present on the equipment?
a circle inside a circle
a rectangle inside a rectangle
a square inside a square
a triangle inside a triangle
The main source of information to check the suitability of an electrical installation is
Electricity at Work Act
IET Wiring Regulations
RIDDOR
PUWER
The Electricity At Work Regulation 1989 are
Non-statutory
Statutory
A code of practice
A training document
Information on the requirements for an initial verification can be found in
Guidance note 5
Guidance note 7
Guidance note 3
Guidance note 1
The purpose of the initial verification process is to verify that the
Installation complies with BS7671
Installation has been completed by a competent person
Tester has the correct test instruments
Necessary paperwork is in place
During this initial verification, checks are carried out to ensure that
Test instruments are calibrated and up to date
All parts of the fixed installation are correctly selected and erected
The tester has the correct qualifications and experience
The serial numbers of the meters are recorded on the certificates
Test leads for use on circuits measuring above 50 volts shall comply with the requirements of
BSEN 60898
BS 7671
BS 88
GS 38
A shop has instructed an electrician to work on the lighting system without isolating the circuit, as the shop owner did not want the shop to be in darkness. The best response would be to
Refuse to do the work and walk off the job
Complete the work taking extra care
Suggest a re-visit when the shop is closed
Complete the work as it has RCD protection
For what reason might isolation of a circuit need to occur on a weekend?
Need to maintain productivity in a factory
Need to maintain overtime work
Avoids the need to notify a loss of supply
So that apprentices can learn the trade
The first action when following the procedures for safely isolating is to
Test the circuit
Safely isolate
Prove the test instrument
Carry out a risk assessment
Which is an example of correctly securing the safe isolation of a circuit?
Leaving a signed label at the isolator
The use of a padlock on an isolator
Turning the isolator into the off position
The use of a fixing device on an isolator
Which statutory document refers to the safe practice when performing inspection and test with regard to those carrying out the test and other people in the building?
BS7671 IET Wiring Regulations
Guidance Notes 3: Inspection and Test
BS7671 On Site Guide
Electricity at Work Regulations 1989
